QuickBooks 2011-2012 occasionally will not accept an IIF file. Instead it will give you multiple line errors and tell you that your data was not imported. To solve do the following:
- Go to Lists > Other Names
- Find your Website Name - It is usually all capitals for instance CANKISU Website.
- Delete your customer name
- Go to Customer Center
- Select Add a new customer
- Enter in your website name exactly how you found it in the 'Other Lists'
- You will not need to enter any other information
- Import your IIF again